package it.pdm.mep;





import android.os.Bundle;
import android.app.Dialog;
import android.content.Context;
import android.graphics.*;
import android.view.MotionEvent;
import android.view.View;


public class ColorPickerDialog extends Dialog { //Finestra di dialogo per la scelta del colore
	
    private static final int CENTER_X = 100;//Coordinate del centro dei cerchi
    private static final int CENTER_Y = 100;
    private static final int CENTER_RADIUS = 32; //Raggio Cerchio interno
    private OnColorChangedListener mListener;
    private int mInitialColor;
	

    public interface OnColorChangedListener {
        void colorChanged(int color);
    }

  

    private static class ColorPickerView extends View {
        private Paint mPaint; //Paint relativo all'arco esterno
        private Paint mCenterPaint; //Paint relativo al cerchio interno
        private final int[] mColors; //Array colori principali
        private OnColorChangedListener mListener;
        private boolean mTrackingCenter;
        private boolean mHighlightCenter;

        ColorPickerView(Context c, OnColorChangedListener l, int color) {
            super(c);
            mListener = l;
            mColors = new int[] { 0xFFFF0000, 0xFFFF00FF, 0xFF0000FF, 0xFF00FFFF, 0xFF00FF00,
                0xFFFFFF00, 0xFFFF0000 }; //Colori principali
            Shader s = new SweepGradient(0, 0, mColors, null); //Creo un arco che distribuisce i colori

            mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); //Creo il paint relativo all'arco creato in precedenza sfumando i colori
            mPaint.setShader(s);
            mPaint.setStyle(Paint.Style.STROKE);
            mPaint.setStrokeWidth(32);

            mCenterPaint = new Paint(Paint.ANTI_ALIAS_FLAG); //Creo un paint che mi serve per disegnare il cerchio interno
            mCenterPaint.setColor(color);
            mCenterPaint.setStrokeWidth(5);
        }

      

        @Override
        protected void onDraw(Canvas canvas) { //Disegno i cerchi sul canvas della finestra di dialogo
            float r = CENTER_X - mPaint.getStrokeWidth()*0.5f;

            canvas.translate(CENTER_X, CENTER_X);

            canvas.drawOval(new RectF(-r, -r, r, r), mPaint); //Disegno sul canvas il cerchio esterno 
            canvas.drawCircle(0, 0, CENTER_RADIUS, mCenterPaint); //Disegno sul canvas il cerchio interno

            if (mTrackingCenter) {
                int c = mCenterPaint.getColor();
                mCenterPaint.setStyle(Paint.Style.STROKE);

                if (mHighlightCenter) {
                    mCenterPaint.setAlpha(0xFF);
                } else {
                    mCenterPaint.setAlpha(0x80);
                }
             canvas.drawCircle(0, 0,  CENTER_RADIUS + mCenterPaint.getStrokeWidth(),mCenterPaint);

                mCenterPaint.setStyle(Paint.Style.FILL);
                mCenterPaint.setColor(c);
            }
        }

        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            setMeasuredDimension(CENTER_X*2, CENTER_Y*2);
        }

    

       

        private int ave(int s, int d, float p) {
            return s + java.lang.Math.round(p * (d - s)); //java.lang.Math.round ritorna il più vicino intero all'argomento passato
        }

        private int interpColor(int colors[], float unit) { //Unit è l'angolo del punto cliccato sulla circonferenza estrena/2*PiGreco, 
        	                                               //da esso la funzione ricava il colore cliccato sul cerchio esterno
            if (unit <= 0) {
                return colors[0];
            }
            if (unit >= 1) {
                return colors[colors.length - 1];
            }

            float p = unit * (colors.length - 1);
            int i = (int)p;
            p -= i;

            int c0 = colors[i];
            int c1 = colors[i+1];
            int a = ave(Color.alpha(c0), Color.alpha(c1), p);
            int r = ave(Color.red(c0), Color.red(c1), p);
            int g = ave(Color.green(c0), Color.green(c1), p);
            int b = ave(Color.blue(c0), Color.blue(c1), p);

            return Color.argb(a, r, g, b);
        }


        private static final float PI = 3.1415926f;

        @Override
        public boolean onTouchEvent(MotionEvent event) {
            float x = event.getX() - CENTER_X;
            float y = event.getY() - CENTER_Y;
            boolean inCenter = java.lang.Math.sqrt(x*x + y*y) <= CENTER_RADIUS;

            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    mTrackingCenter = inCenter;
                    if (inCenter) {
                        mHighlightCenter = true;
                        invalidate();
                        break;
                    }
                case MotionEvent.ACTION_MOVE:
                    if (mTrackingCenter) {
                        if (mHighlightCenter != inCenter) {
                            mHighlightCenter = inCenter;
                            invalidate();
                        }
                    } else {
                        float angle = (float)java.lang.Math.atan2(y, x);
                        // need to turn angle [-PI ... PI] into unit [0....1]
                        float unit = angle/(2*PI);
                        if (unit < 0) {
                            unit += 1;
                        }
                        mCenterPaint.setColor(interpColor(mColors, unit));
                        invalidate();
                    }
                    break;
                case MotionEvent.ACTION_UP:
                    if (mTrackingCenter) {
                        if (inCenter) {
                            mListener.colorChanged(mCenterPaint.getColor());
                        }
                        mTrackingCenter = false;    // so we draw w/o halo
                        invalidate();
                    }
                    break;
            }
            return true;
        }
    }

    public ColorPickerDialog(Context context, OnColorChangedListener listener,int initialColor) {
        super(context);

        mListener = listener;
        mInitialColor = initialColor;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        OnColorChangedListener l = new OnColorChangedListener() {
            public void colorChanged(int color) {
                mListener.colorChanged(color);
                dismiss();
            }
        };

        setContentView(new ColorPickerView(getContext(), l, mInitialColor));
        setTitle("Scegli un colore");
       
    }
}